Transmission line lightning strike point positioning system and method and medium

Abstract

The present invention relates to the technical field of lightning protection for electric lines, and discloses a system and method for locating lightning strike points on power transmission lines, as well as a medium. The system comprises: an elliptical coordinate system construction module for performing principal component analysis on the registered voltage data of the power transmission line during normal operation to obtain principal component data of the registered voltage data, and constructing an elliptical coordinate system for the power transmission line during normal operation; a lightning signal screening module for performing principal component analysis on the real-time voltage data of the power transmission line to obtain principal component data of the real-time voltage data, screening out the real-time voltage data located outside and within the boundary of the elliptical coordinate system, and determining the lightning transient signal on the power transmission line using an elliptical algorithm; and a lightning strike point distance positioning module for detecting the voltage traveling wave of the lightning transient signal on the power transmission line, and determining the position of the lightning strike point using the traveling wave transmission theory. The present invention has important practical significance for quickly detecting the lightning strike point, measuring the distance to the lightning strike point, eliminating the lightning strike point, and repairing the fault.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning protection for power transmission lines, and in particular to a system and method for locating a lightning strike point on a power transmission line, as well as a medium. Background Art

[0002] Transmission lines, as a crucial component of the power system, are the arteries of the electric power industry. During frequent thunderstorms, lightning strikes frequently occur on transmission lines, directly impacting the safe and stable operation of power lines and, in turn, the normal operation of power supply services. Accurately measuring the distance to lightning strike points is crucial for improving troubleshooting efficiency.

[0003] Currently, the location of lightning strike points is a topic of research by many experts and scholars. For example, current sensors installed on towers collect lightning current signals and establish distributed monitoring systems to locate lightning strike points. However, transmission lines are subject to numerous lightning strikes, and only lightning strike points during faulty conditions are considered, while those during non-faulty conditions are overlooked. Lightning strikes can pose hidden dangers to transmission lines, and these non-faulty lightning strikes also need to be located to provide data support for transmission line operation and maintenance. An improved two-terminal traveling wave method based on wavelet transform and traveling wave theory is used to locate lightning strike points on transmission lines. However, this method is uncertain because the collected traveling wave velocity is easily affected by factors such as line parameters, geographic location, and climate. This results in significant errors between the calculated and actual results of traveling wave ranging. Summary of the Invention

[0004] The present invention aims to overcome the aforementioned problems of the prior art by providing a system and method for locating lightning strike points on power transmission lines, as well as a medium. This system and method utilizes an ellipse algorithm to effectively and accurately detect lightning strike points. It employs a synchronous traveling wave method at both ends of the transmission line, independent of the mother wavelet, eliminating the inconvenience of requiring a single-cycle traveling wave data window. This system and method are of great practical significance for rapidly detecting and ranging lightning strike points, eliminating lightning strike point errors, and repairing faults.

[0005] In order to achieve the above-mentioned object, the present invention provides a transmission line lightning strike point location system, comprising:

[0006] The elliptical coordinate system construction module is used to perform principal component analysis on the parasitic voltage data when the transmission line is operating normally, obtain principal component data of the parasitic voltage data, project the principal component data of the parasitic voltage data onto the principal component coordinate system, and construct the elliptical coordinate system when the transmission line is operating normally;

[0007] The lightning signal screening module is used to perform principal component analysis on the real-time voltage data of the transmission line, obtain the principal component data of the real-time voltage data, project the principal component data of the real-time voltage data into an elliptical coordinate system when the transmission line is operating normally, screen out the real-time voltage data located outside and inside the boundary of the elliptical coordinate system, and determine the lightning transient signal on the transmission line using an elliptical algorithm based on the real-time voltage data located outside and inside the boundary of the elliptical coordinate system;

[0008] The lightning strike point distance positioning module is used to detect the voltage traveling wave of the lightning transient signal on the transmission line, and determine the location of the lightning strike point based on the voltage traveling wave of the lightning transient signal on the transmission line through the traveling wave transmission theory.

[0009] Furthermore, a specific method of performing principal component analysis on the parasitic voltage data when the transmission line is operating normally to obtain principal component data of the parasitic voltage data includes:

[0010] The n parasitic voltage data of the transmission line during normal operation are analyzed in different data windows of p samples, and the parasitic voltage data during normal operation are expressed as a p-dimensional vector:

[0011] x i =[x i,1 x i,2 x i,3 x i,4 …x i,p ]

[0012] Where x i represents the registered voltage data of the i-th transmission line when it is working normally, i = 1, 2, 3, ... n; x i,p represents the pth sample of the registered voltage data when the i-th transmission line is operating normally;

[0013] A total of n transmission lines' parasitic voltage data when operating normally are used to form the matrix X:

[0014]

[0015] Where x(n,p) represents the pth sample of the nth registered voltage data when the transmission line is operating normally;

[0016] Calculate the mean vector of the normalized matrix J of the X matrix The calculation method is:

[0017]

[0018] Where j(i,p) represents the value of the i-th row and p-th column of the normalized matrix J of the X matrix; i = 1, 2, 3, ... n;

[0019] Calculate the variance-covariance matrix S as follows:

[0020]

[0021] Where, j i Represents the row vector of the i-th row of the normalized matrix J matrix;

[0022] Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S, and the eigenvector is represented by μ:

[0023] μ1=[μ 1,1 ,μ 1,2 ,μ 1,3 …,μ 1,p ] T

[0024] μ2=[μ 2,1 ,μ 2,2 ,μ 2,3 …,μ 2,p ] T

[0025] …

[0026] μ n =[μ n,1 ,μ n,2 ,μ n,3 …,μ n,p ] T

[0027] Where μ n represents the nth eigenvector of the variance-covariance matrix S; μ n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S;

[0028] The eigenvalue is denoted by λ:

[0029] λ=[λ1,λ2,λ3,...,λ p ]

[0030] Where λ p represents the pth eigenvalue of the variance-covariance matrix S;

[0031] Calculate the principal component data of the registered voltage data using the following method:

[0032]

[0033] Where z n Represents the principal component data of the calculated n-th register voltage data, which is a 1×p row vector; μ n Trepresents the transposed vector of the nth eigenvector of the variance-covariance matrix S; j represents each row vector of the normalized matrix J; μ T Represents the transpose of the matrix consisting of the n eigenvectors of the variance-covariance matrix S.

[0034] Furthermore, the elliptical equation corresponding to the elliptical coordinate system when the transmission line is operating normally is:

[0035]

[0036] Where EE is the calculated value of the ellipse equation, PC is 1r and PC 2r Represents the first two principal component data of any phase of the elliptical pattern during normal operation; PC 1max Represents the major semi-axis of the elliptical pattern; PC 2max Represents the semi-minor axis of the ellipse pattern.

[0037] Furthermore, principal component analysis is performed on the real-time voltage data of the transmission line. The specific method for obtaining principal component data of the real-time voltage data is as follows:

[0038] The n real-time voltage data of the transmission line are analyzed in different data windows of p samples, with an interval of 1 μs between samples. The real-time voltage data of the transmission line are represented as a p-dimensional vector:

[0039] x′ i =[x′ i,1 x′ i,2 x′ i,3 x′ i,4 …x′ i,p ]

[0040] Where x' i represents the i-th real-time voltage data, i=1, 2, 3, ... n; x' i,p represents the pth sample of the i-th real-time voltage data;

[0041] The real-time voltage data of n transmission lines are used to form the matrix X':

[0042]

[0043] Where x'(n,p) represents the pth sample of the nth real-time voltage data of the transmission line;

[0044] Calculate the mean vector of the normalized matrix J' of the X' matrix The calculation method is:

[0045]

[0046] Where j'(i,p) represents the value of the i-th row and p-th column of the normalized matrix J' of the X' matrix; i = 1, 2, 3, ... n;

[0047] Calculate the variance-covariance matrix S' using the following method:

[0048]

[0049] Where, j' i The row vector representing the i-th row of the normalized matrix J'.

[0050] Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S', and the eigenvector is represented by μ':

[0051] μ′1=[μ′ 1,1 ,μ′ 1,2 ,μ′ 1,3 …,μ′ 1,p ] T

[0052] μ′2=[μ′ 2,1 ,μ′ 2,2 ,μ′ 2,3 …,μ′ 2,p ] T

[0053] …

[0054] μ′ n =[μ′ n,1 ,μ′ n,2 ,μ′ n,3 …,μ′ n,p ] T

[0055] Where μ' n represents the nth eigenvector of the variance-covariance matrix S'; μ' n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S';

[0056] The eigenvalue is denoted by λ':

[0057] λ′=[λ′1,λ′2,λ′3,...,λ′ p ]

[0058] Where λ' p represents the pth eigenvalue of the variance-covariance matrix S';

[0059] Calculate the principal component data of real-time voltage data using the following method:

[0060]

[0061] Where z' n represents the principal component data of the calculated n-th real-time voltage data, which is a 1×p row vector; μ' n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S'; j' represents each row vector of the normalized matrix J'; μ' T Represents the transpose of the matrix consisting of the nth eigenvectors of the variance-covariance matrix S'.

[0062] Furthermore, based on the real-time voltage data outside and inside the boundary of the elliptical coordinate system, the specific method for determining the lightning transient signal on the transmission line using the elliptical algorithm is as follows:

[0063] The Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated using the following method:

[0064]

[0065] Where Δdk represents the Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the origin of the elliptical coordinate system when the transmission line is operating normally; f i represents the elliptical coordinates corresponding to the i-th real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally; f o represents the coordinates of the origin of the elliptical coordinate system when the transmission line is operating normally; h represents the number of principal component data of the real-time voltage data located outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally;

[0066] The Euclidean tolerance EN between the real-time voltage data outside and inside the boundary of the elliptical coordinate system and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated as follows:

[0067]

[0068] The components for distinguishing lightning transient signals on transmission lines are as follows:

[0069]

[0070] Wherein, F represents a logical value. When F=0, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a switching operation. When F=1, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a lightning transient signal on the transmission line. ε is a threshold value.

[0071] Furthermore, the specific method for detecting the voltage traveling wave of the lightning transient signal on the transmission line and determining the location of the lightning strike point based on the voltage traveling wave of the lightning transient signal on the transmission line using the traveling wave transmission theory is as follows:

[0072] Detecting a voltage traveling wave of a lightning transient signal on a transmission line, collecting voltage data points of the voltage traveling wave, and determining, according to a counting scheme, a number s1 of voltage data points of the voltage traveling wave detected by a front-end protection relay of the transmission line and a number s2 of voltage data points of the voltage traveling wave detected by a rear-end protection relay of the transmission line;

[0073] When s1 < s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is:

[0074] Δt=S a ×(s1-s2)

[0075]

[0076] Where t1 is the time it takes for the voltage traveling wave to propagate from the lightning strike point to the front-end protection relay of the transmission line, t2 is the time it takes for the voltage traveling wave to propagate from the lightning strike point to the rear-end protection relay of the transmission line, Δt is the time difference between t1 and t2, and t total represents the sum of t1 and t2, S a Indicates the sampling rate of the protection relay;

[0077] When s1>s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is:

[0078] Δt=S a ×(s1-s2)

[0079]

[0080] The method for calculating the distance from the lightning strike point based on the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends is:

[0081] d1=ct1

[0082] d2=ct2

[0083] Where d1 represents the distance from the lightning strike point to the front-end protection relay; d2 represents the distance from the lightning strike point to the rear-end protection relay; and c represents the speed of voltage traveling wave propagation.

[0084] A second aspect of the present invention provides a method for locating a lightning strike point on a transmission line, comprising:

[0085] Performing principal component analysis on the parasitic voltage data when the transmission line is operating normally to obtain principal component data of the parasitic voltage data, projecting the principal component data of the parasitic voltage data onto a principal component coordinate system, and constructing an elliptical coordinate system when the transmission line is operating normally;

[0086] Performing principal component analysis on the real-time voltage data of the transmission line to obtain principal component data of the real-time voltage data, projecting the principal component data of the real-time voltage data into an elliptical coordinate system when the transmission line is operating normally, screening out real-time voltage data located outside and inside the boundary of the elliptical coordinate system, and determining the lightning transient signal on the transmission line using an elliptical algorithm based on the real-time voltage data located outside and inside the boundary of the elliptical coordinate system;

[0087] The voltage traveling wave of the lightning transient signal on the transmission line is detected, and the location of the lightning strike point is determined based on the voltage traveling wave of the lightning transient signal on the transmission line through the traveling wave transmission theory.

[0088] Furthermore, a specific method of performing principal component analysis on the parasitic voltage data when the transmission line is operating normally to obtain principal component data of the parasitic voltage data includes:

[0089] The n parasitic voltage data of the transmission line during normal operation are analyzed in different data windows of p samples, and the parasitic voltage data during normal operation are expressed as a p-dimensional vector:

[0090] x i =[x i,1 x i,2 x i,3 x i,4 … x i,p ]

[0091] Where x i represents the registered voltage data of the i-th transmission line when it is working normally, i = 1, 2, 3, ... n; x i,p represents the pth sample of the registered voltage data when the i-th transmission line is operating normally;

[0092] A total of n transmission lines' parasitic voltage data when operating normally are used to form the matrix X:

[0093]

[0094] Where x(n,p) represents the pth sample of the nth registered voltage data when the transmission line is operating normally;

[0095] Calculate the mean vector of the normalized matrix J of the X matrix The calculation method is:

[0096]

[0097] Where j(i,p) represents the value of the i-th row and p-th column of the normalized matrix J of the X matrix; i = 1, 2, 3, ... n;

[0098] Calculate the variance-covariance matrix S as follows:

[0099]

[0100] Where, j i Represents the row vector of the i-th row of the normalized matrix J matrix;

[0101] Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S, and the eigenvector is represented by μ:

[0102] μ1=[μ 1,1 ,μ 1,2 ,μ 1,3 …,μ 1,p ] T

[0103] μ2=[μ 2,1 ,μ 2,2 ,μ 2,3 …,μ 2,p ] T

[0104] …

[0105] μ n =[μ n,1 ,μ n,2 ,μ n,3 …,μ n,p ] T

[0106] Where μ n represents the nth eigenvector of the variance-covariance matrix S; μ n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S;

[0107] The eigenvalue is denoted by λ:

[0108] λ=[λ1,λ2,λ3,...,λ p ]

[0109] Where λ p represents the pth eigenvalue of the variance-covariance matrix S;

[0110] Calculate the principal component data of the registered voltage data using the following method:

[0111]

[0112] Where zn Represents the principal component data of the calculated n-th register voltage data, which is a 1×p row vector; μ n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S; j represents each row vector of the normalized matrix J; μ T Represents the transpose of the matrix consisting of the n eigenvectors of the variance-covariance matrix S.

[0113] Furthermore, the elliptical equation corresponding to the elliptical coordinate system when the transmission line is operating normally is:

[0114]

[0115] Where EE is the calculated value of the ellipse equation, PC is 1r and PC 2r Represents the first two principal component data of any phase of the elliptical pattern during normal operation; PC 1max Represents the major semi-axis of the elliptical pattern; PC 2max Represents the semi-minor axis of the ellipse pattern.

[0116] Furthermore, principal component analysis is performed on the real-time voltage data of the transmission line. The specific method for obtaining principal component data of the real-time voltage data is as follows:

[0117] The n real-time voltage data of the transmission line are analyzed in different data windows of p samples, with an interval of 1 μs between samples. The real-time voltage data of the transmission line are represented as a p-dimensional vector:

[0118] x′ i =[x′ i,1 x′ i,2 x′ i,3 x′ i,4 … x′ i,p ]

[0119] Where x' i represents the i-th real-time voltage data, i=1, 2, 3, ... n; x' i,p represents the pth sample of the i-th real-time voltage data;

[0120] The real-time voltage data of n transmission lines are used to form the matrix X':

[0121]

[0122] Where x'(n,p) represents the pth sample of the nth real-time voltage data of the transmission line;

[0123] Calculate the mean vector of the normalized matrix J' of the X' matrix The calculation method is:

[0124]

[0125] Where j'(i,p) represents the value of the i-th row and p-th column of the normalized matrix J' of the X' matrix; i = 1, 2, 3, ... n;

[0126] Calculate the variance-covariance matrix S' using the following method:

[0127]

[0128] Where, j' i The row vector representing the i-th row of the normalized matrix J'.

[0129] Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S', and the eigenvector is represented by μ':

[0130] μ′1=[μ′ 1,1 ,μ′ 1,2 ,μ′ 1,3 …,μ′ 1,p ] T

[0131] μ′2=[μ′ 2,1 ,μ′ 2,2 ,μ′ 2,3 …,μ′ 2,p ] T

[0132] …

[0133] μ′ n =[μ′ n,1 ,μ′ n,2 ,μ′ n,3 …,μ′ n,p ] T

[0134] Where μ' n represents the nth eigenvector of the variance-covariance matrix S'; μ' n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S';

[0135] The eigenvalue is denoted by λ':

[0136] λ′=[λ′1,λ′2,λ′3,...,λ′ p ]

[0137] Where λ' p represents the pth eigenvalue of the variance-covariance matrix S';

[0138] Calculate the principal component data of real-time voltage data using the following method:

[0139]

[0140] Where z' n represents the principal component data of the calculated n-th real-time voltage data, which is a 1×p row vector; μ' n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S'; j' represents each row vector of the normalized matrix J'; μ' T Represents the transpose of the matrix consisting of the nth eigenvectors of the variance-covariance matrix S'.

[0141] Furthermore, based on the real-time voltage data outside and inside the boundary of the elliptical coordinate system, the specific method for determining the lightning transient signal on the transmission line using the elliptical algorithm is as follows:

[0142] The Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated using the following method:

[0143]

[0144] Where Δdk represents the Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the origin of the elliptical coordinate system when the transmission line is operating normally; f i represents the elliptical coordinates corresponding to the i-th real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally; f o represents the coordinates of the origin of the elliptical coordinate system when the transmission line is operating normally; h represents the number of principal component data of the real-time voltage data located outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally;

[0145] The Euclidean tolerance EN between the real-time voltage data outside and inside the boundary of the elliptical coordinate system and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated as follows:

[0146]

[0147] The components for distinguishing lightning transient signals on transmission lines are as follows:

[0148]

[0149] Wherein, F represents a logical value. When F=0, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a switching operation. When F=1, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a lightning transient signal on the transmission line. ε is a threshold value.

[0150] Furthermore, the specific method for detecting the voltage traveling wave of the lightning transient signal on the transmission line and determining the location of the lightning strike point based on the voltage traveling wave of the lightning transient signal on the transmission line using the traveling wave transmission theory is as follows:

[0151] Detecting a voltage traveling wave of a lightning transient signal on a transmission line, collecting voltage data points of the voltage traveling wave, and determining, according to a counting scheme, a number s1 of voltage data points of the voltage traveling wave detected by a front-end protection relay of the transmission line and a number s2 of voltage data points of the voltage traveling wave detected by a rear-end protection relay of the transmission line;

[0152] When s1 < s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is:

[0153] Δt=S a ×(s1-s2)

[0154]

[0155] Where t1 is the time it takes for the voltage traveling wave to propagate from the lightning strike point to the front-end protection relay of the transmission line, t2 is the time it takes for the voltage traveling wave to propagate from the lightning strike point to the rear-end protection relay of the transmission line, Δt is the time difference between t1 and t2, and t total represents the sum of t1 and t2, S a Indicates the sampling rate of the protection relay;

[0156] When s1>s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is:

[0157] Δt=S a ×(s1-s2)

[0158]

[0159] The method for calculating the distance from the lightning strike point based on the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends is:

[0160] d1=ct1

[0161] d2=ct2

[0162] Where d1 represents the distance from the lightning strike point to the front-end protection relay; d2 represents the distance from the lightning strike point to the rear-end protection relay; and c represents the speed of voltage traveling wave propagation.

[0163] A third aspect of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0164] The present invention first performs principal component analysis on the parasitic voltage data of the transmission line during normal operation to obtain principal component data of the parasitic voltage data, projects the principal component data of the parasitic voltage data onto a principal component coordinate system, and constructs an elliptical coordinate system for the transmission line during normal operation; then performs principal component analysis on the real-time voltage data of the transmission line to obtain principal component data of the real-time voltage data, projects the principal component data of the real-time voltage data onto the elliptical coordinate system for the transmission line during normal operation, filters out real-time voltage data located outside and within the boundaries of the elliptical coordinate system for the transmission line during normal operation, and uses an elliptical algorithm to determine the lightning transient signal on the transmission line based on the real-time voltage data located outside and within the boundaries of the elliptical coordinate system for the transmission line during normal operation; finally, based on the voltage traveling wave of the lightning transient signal on the transmission line and based on a synchronous traveling wave method recorded at both ends of the transmission line, the distance from the lightning fault point to the protection relay can be calculated. This has important practical significance for quickly detecting the lightning strike point, measuring the distance to the lightning strike point, eliminating the lightning strike point, and repairing the fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0165] Figure 1 It is a structural schematic diagram of the present invention;

[0166] Figure 2 This is a schematic diagram of the principle of calculating the distance to the lightning strike point according to the present invention;

[0167] Figure 3 This is a schematic diagram of the principle of calculating the distance to the lightning strike point according to the present invention;

[0168] Figure 4 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0169] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0170] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0171] Example 1

[0172] like Figure 1 The transmission line lightning strike point positioning system shown in the figure includes an elliptical coordinate system construction module, a lightning strike signal screening module and a lightning strike point distance positioning module;

[0173] The elliptical coordinate system construction module is used to perform principal component analysis on the parasitic voltage data (voltage data of a certain period when the transmission line is operating normally) when the transmission line is operating normally (principal component analysis can extract its eigenvectors after offline analysis of the data matrix. In this case, only these eigenvectors need to be used to perform online analysis on new signals. Therefore, real-time signals can be continuously analyzed in the power system), obtain the principal component data of the parasitic voltage data, project the principal component data of the parasitic voltage data onto the principal component coordinate system (a coordinate system whose horizontal and vertical coordinates are both principal components), and construct the elliptical coordinate system when the transmission line is operating normally (after processing the normal operating signal through principal component analysis, the signals of a voltage signal period are sequentially projected onto the principal component coordinate system, and these signals will form an elliptical pattern. This elliptical pattern is the elliptical coordinate system when the transmission line is operating normally);

[0174] The lightning signal screening module is used to perform principal component analysis on the real-time voltage data of the transmission line (this is to detect interference signals, because by using the operating voltage x of the transmission line as a reference, an elliptical pattern representing its operating state can be determined. Therefore, when any interference occurs, the first wavefront of the incremental signal Dx1 will be generated, and this wavefront has different characteristics from the wavefront corresponding to the elliptical pattern). The module obtains the principal component data of the real-time voltage data, projects the principal component data of the real-time voltage data into the elliptical coordinate system when the transmission line is operating normally, and screens out the real-time voltage data located outside and inside the boundaries of the elliptical coordinate system when the transmission line is operating normally. Based on the real-time voltage data located outside and inside the boundaries of the elliptical coordinate system when the transmission line is operating normally, the module uses the elliptical algorithm to determine the lightning transient signal on the transmission line.

[0175] The lightning strike point distance positioning module is used to detect the voltage traveling wave of the lightning transient signal on the transmission line, and determine the location of the lightning strike point based on the voltage traveling wave of the lightning transient signal on the transmission line through the traveling wave transmission theory.

[0176] Furthermore, in the present invention, principal component analysis is performed on the parasitic voltage data when the transmission line is operating normally, and a specific method for obtaining principal component data of the parasitic voltage data includes:

[0177] The n parasitic voltage data points during normal operation of the transmission line are analyzed in different data windows of p samples. (The voltage signal in this stage is a discrete sine wave f(x) recorded in a periodic data window. Since the sampling frequency in this stage is 1 MHz, the duration of one period is 25 μs. Therefore, if 25 sample points are taken, the step size is 1 μs. If the number of samples is changed, the sample interval will change accordingly. The more samples taken, the smaller the sample interval will be (the number of samples × sample interval = 25 μs must be satisfied). The parasitic voltage data during normal operation is represented as a p-dimensional vector (in this embodiment, p is 25, and the interval between samples is 1 μs):

[0178] x i =[x i,1 x i,2 x i,3 x i,4 … x i,p ]

[0179] Where x i represents the registered voltage data of the i-th transmission line when it is working normally, i = 1, 2, 3, ... n; x i,p represents the pth sample of the registered voltage data when the i-th transmission line is operating normally;

[0180] A total of n (n is 2400 in this embodiment) parasitic voltage data of transmission lines in normal operation are used to form the matrix X:

[0181]

[0182] Wherein, x(n,p) represents the p-th sample of the n-th registered voltage data when the transmission line operates normally.

[0183] Calculate the mean vector of the normalized matrix J of the X matrix , the calculation method is:

[0184]

[0185] Where j(i,p) represents the value of the i-th row and p-th column of the normalized matrix J of the X matrix; i = 1, 2, 3, ... n;

[0186] Calculate the variance-covariance matrix S as follows:

[0187]

[0188] Where, j i Represents the row vector of the i-th row (1×p) of the normalized matrix J matrix;

[0189] Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S, where the eigenvectors are represented by μ (25 eigenvectors are required in this embodiment):

[0190] μ1=[μ 1,1 ,μ 1,2 ,μ 1,3 …,μ 1,p ] T

[0191] μ2=[μ 2,1 ,μ 2,2 ,μ 2,3 …,μ 2,p ] T

[0192] …

[0193] μ n =[μ n,1 ,μ n,2 ,μ n,3 …,μ n,p ] T

[0194] Where μ n represents the nth eigenvector of the variance-covariance matrix S; μ n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S;

[0195] The eigenvalue is represented by λ (25 eigenvalues ​​are required in this embodiment):

[0196] λ=[λ1,λ2,λ3,...,λ p ]

[0197] Where λ p represents the pth eigenvalue of the variance-covariance matrix S;

[0198] Calculate the principal component data (n×p) of the register voltage data using the following method:

[0199]

[0200] Where z n Represents the principal component data of the calculated nth register voltage data, which is a 1×p row vector; μ n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S; j represents each row vector of the normalized matrix J; μ TRepresents the transpose of the matrix consisting of the n eigenvectors of the variance-covariance matrix S.

[0201] In the present invention, the elliptical equation corresponding to the elliptical coordinate system when the transmission line operates normally is:

[0202]

[0203] Where EE is the calculated value of the ellipse equation, PC is 1r and PC 2r Represents the first two principal component data of any phase of the elliptical pattern during normal operation (these two principal component data determine a coordinate point, which is equivalent to the values ​​of x and y in the xy axis coordinate system), that is, (PC 1r , PC 2r ) is the coordinate point corresponding to any phase in the principal component coordinate system; PC 1max Represents the major semi-axis of the elliptical pattern; PC 2max Represents the semi-minor axis of the ellipse pattern.

[0204] Furthermore, in the present invention, principal component analysis is performed on the real-time voltage data of the transmission line, and the specific method for obtaining the principal component data of the real-time voltage data is:

[0205] The n real-time voltage data of the transmission line are analyzed in different data windows of p samples, with an interval of 1 μs between samples. The real-time voltage data of the transmission line are represented as a p-dimensional vector:

[0206] x′ i =[x′ i,1 x′ i,2 x′ i,3 x′ i,4 … x′ i,p ]

[0207] Where x' i represents the i-th real-time voltage data, i=1, 2, 3, ... n; x' i,p represents the pth sample of the i-th real-time voltage data;

[0208] The real-time voltage data of n transmission lines are used to form the matrix X':

[0209]

[0210] Where x'(n,p) represents the pth sample of the nth real-time voltage data of the transmission line;

[0211] Calculate the mean vector of the normalized matrix J' of the X' matrix The calculation method is:

[0212]

[0213] Where j'(i,p) represents the value of the i-th row and p-th column of the normalized matrix J' of the X' matrix; i = 1, 2, 3, ... n;

[0214] Calculate the variance-covariance matrix S' using the following method:

[0215]

[0216] Where, j' i Represents the row vector of the i-th row (1×p) of the normalized matrix J'.

[0217] Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S', and the eigenvector is represented by μ':

[0218] μ′1=[μ′ 1,1 ,μ′ 1,2 ,μ′ 1,3 …,μ′ 1,p ] T

[0219] μ′2=[μ′ 2,1 ,μ′ 2,2 ,μ′ 2,3 …,μ′ 2,p ] T

[0220] …

[0221] μ′ n =[μ′ n,1 ,μ′ n,2 ,μ′ n,3 …,μ′ n,p ] T

[0222] Where μ' n represents the nth eigenvector of the variance-covariance matrix S'; μ' n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S';

[0223] The eigenvalue is denoted by λ':

[0224] λ′=[λ′1,λ′2,λ′3,...,λ′ p ]

[0225] Where λ' p represents the pth eigenvalue of the variance-covariance matrix S';

[0226] Calculate the principal component data (n×p) of the real-time voltage data using the following method:

[0227]

[0228] Where z' n represents the principal component data of the calculated n-th real-time voltage data, which is a 1×p row vector; μ' n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S'; j' represents each row vector of the normalized matrix J'; μ' T Represents the transpose of the matrix consisting of the nth eigenvectors of the variance-covariance matrix S'.

[0229] In the present invention, the principal component data of the real-time voltage data is projected onto the elliptical coordinate system when the transmission line is operating normally, wherein the principal component values ​​of the real-time voltage data located outside and within the boundary of the elliptical coordinate system when the transmission line is operating normally (i.e., the real-time voltage data not on the boundary of the elliptical coordinate system when the transmission line is operating normally; the principal component data of the real-time voltage data can be substituted into the elliptical equation corresponding to the elliptical coordinate system when the transmission line is operating normally to calculate the EE value corresponding to the real-time voltage data, and the calculated EE is used to determine whether the real-time voltage data is on the boundary of the elliptical coordinate system when the transmission line is operating normally; when EE is less than 1, it means that the real-time voltage data is inside the boundary of the elliptical coordinate system when the transmission line is operating normally; when EE is greater than 1, it means that the real-time voltage data is outside the boundary of the elliptical coordinate system when the transmission line is operating normally, that is, exceeds the boundary of the elliptical coordinate system; when EE=1, it means that the real-time voltage data is on the boundary of the elliptical coordinate system when the transmission line is operating normally, which represents a normal operating state) show a certain regularity, indicating the trajectory of the interference type. Based on this feature, the Euclidean tolerance EN between these principal component values ​​and the origin (0, 0) of the elliptical coordinate system when the transmission line is working normally can be calculated to determine the type of interference phenomenon.

[0230] Furthermore, based on the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally, the specific method for determining the lightning transient signal on the transmission line using the elliptical algorithm is as follows:

[0231] The Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated using the following method:

[0232]

[0233] Where Δdk represents the Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the original elliptical coordinate system when the transmission line is operating normally; f irepresents the elliptical coordinates corresponding to the i-th real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally; f o represents the coordinates (0, 0) of the origin of the elliptical coordinate system when the transmission line is operating normally; h represents the number of principal component data of the real-time voltage data located outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally;

[0234] The Euclidean tolerance EN between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated as follows:

[0235]

[0236] The components for distinguishing lightning transient signals on transmission lines are as follows:

[0237]

[0238] In the formula, F represents a logical value, which is used as a discriminant element. The identification of the interference type is achieved by calculating the normalized values ​​of n new continuous vectors. Since the Euclidean normal value of the switching operation is less than the lightning strike, if the Euclidean normal value is less than or equal to the threshold, that is, F = 0, then the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a switching operation (transmission line switching operation is a power system technical measure used to adjust the phase sequence of one or more transmission lines in the power grid; switching operation can also cause traveling wave anomalies, but it is not a lightning strike point fault). When F = 1, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a lightning transient signal on the transmission line; ε is a threshold (the threshold in the present invention is determined based on the specific situation in actual application and can be selected by multiple simulations of lightning strike faults and normal operation conditions).

[0239] In the technical solution of the present invention, the voltage traveling wave of the lightning transient signal on the transmission line is detected, and the specific method for determining the location of the lightning strike point based on the voltage traveling wave of the lightning transient signal on the transmission line using the traveling wave transmission theory is as follows:

[0240] Detecting a voltage traveling wave of a lightning transient signal on a transmission line, collecting voltage data points of the voltage traveling wave, and determining, according to a counting scheme, a number s1 of voltage data points of the voltage traveling wave detected by a front-end protection relay of the transmission line and a number s2 of voltage data points of the voltage traveling wave detected by a rear-end protection relay of the transmission line;

[0241] When s1 < s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is:

[0242] Δt=Sa ×(s1 - s2)

[0243]

[0244] Wherein, t1 is the time for the voltage traveling wave to propagate from the lightning strike point to the front-end protection relay of the transmission line, t2 is the time for the voltage traveling wave to propagate from the lightning strike point to the rear-end protection relay of the transmission line, Δt is the time difference between t1 and t2, and t total represents the sum of t1 and t2, and S a represents the sampling rate of the protection relay (the sampling rate of the front-end protection relay is the same as that of the rear-end protection relay);

[0245] When s1 > s2, the time for the voltage traveling wave to propagate from the lightning strike point to the two-end protection relays is calculated, and the expression is:

[0246] Δt = S a ×(s1 - s2)

[0247]

[0248] The method for calculating the distance of the lightning strike point based on the time for the voltage traveling wave to propagate from the lightning strike point to the two-end protection relays is:

[0249] d1 = ct1

[0250] d2 = ct2

[0251] Wherein, d1 represents the distance from the lightning strike point to the front-end protection relay; d2 represents the distance from the lightning strike point to the rear-end protection relay; c represents the propagation speed of the voltage traveling wave.

[0252] In the present invention, after calculating d1 and d2, the distance results d1 and d2 of the lightning strike point can be output.

[0253] In the present invention, the calculation principle of the lightning strike point distance is as follows:

[0254] When a lightning strike fault occurs at point F on the transmission line, a fault voltage traveling wave will be generated at the lightning strike fault point F and propagate to both ends of the line. d1 and d2 are respectively the distances from the lightning strike fault point F to the measurement end R (front-end protection relay) and the measurement end I (rear-end protection relay), L is the total length of the transmission line, t1 is the time for the fault voltage traveling wave to propagate from the lightning strike fault point to the measurement end R, t2 is the time for the fault voltage traveling wave to propagate from the lightning strike fault point to the measurement end I, and t total represents the sum of t1 and t2, that is, the time for the fault voltage traveling wave to propagate from the front-end protection relay to the rear-end protection relay; when s1 < s2 (i.e., d1 < d2), as Figure 2As shown, the measuring terminal R receives the forward fault voltage traveling wave propagating from the lightning fault point, and the measuring terminal I receives the backward fault voltage traveling wave propagating from the lightning fault point. The corresponding formula can be used to calculate Δt, t1, and t2. When s1>s2 (i.e., d1>d2), as shown Figure 3 As shown, the measuring terminal R receives the fault voltage traveling wave propagated from the lightning fault point, and the measuring terminal I receives the fault voltage traveling wave propagated from the lightning fault point. The corresponding formula can be used to calculate Δt, t1, and t2; and then the distance to the lightning strike point can be further calculated.

[0255] Example 2

[0256] like Figure 4 The method for locating the lightning strike point on a transmission line shown includes:

[0257] Perform principal component analysis on the parasitic voltage data (voltage data of a certain period when the transmission line is operating normally) when the transmission line is operating normally (principal component analysis can extract eigenvectors after offline analysis of the data matrix. In this case, new signals can be analyzed online using only these eigenvectors. Therefore, real-time signals can be continuously analyzed in the power system), obtain principal component data of the parasitic voltage data, project the principal component data of the parasitic voltage data onto a principal component coordinate system (a coordinate system whose horizontal and vertical coordinates are both principal components), and construct an elliptical coordinate system when the transmission line is operating normally (after processing the normal operating signal through principal component analysis, the signals of a voltage signal period are sequentially projected onto the principal component coordinate system, and these signals will form an elliptical pattern. This elliptical pattern is the elliptical coordinate system when the transmission line is operating normally);

[0258] Performing principal component analysis on the real-time voltage data of the transmission line (this is done to detect interference signals, because an elliptical pattern representing the operating state of the transmission line can be determined based on the operating voltage x of the transmission line. Therefore, when any interference occurs, a first wavefront of the incremental signal Dx1 is generated, and this wavefront has different characteristics from the wavefront corresponding to the elliptical pattern). Obtaining principal component data of the real-time voltage data, projecting the principal component data of the real-time voltage data onto an elliptical coordinate system when the transmission line is operating normally, screening out real-time voltage data located both within and outside the boundaries of the elliptical coordinate system when the transmission line is operating normally, and using an elliptical algorithm to determine the lightning transient signal on the transmission line based on the real-time voltage data located both within and outside the boundaries of the elliptical coordinate system when the transmission line is operating normally.

[0259] The voltage traveling wave of the lightning transient signal on the transmission line is detected, and the location of the lightning strike point is determined based on the voltage traveling wave of the lightning transient signal on the transmission line through the traveling wave transmission theory.

[0260] Furthermore, in the present invention, principal component analysis is performed on the parasitic voltage data when the transmission line is operating normally, and a specific method for obtaining principal component data of the parasitic voltage data includes:

[0261] The n parasitic voltage data points during normal operation of the transmission line are analyzed in different data windows of p samples. (The voltage signal in this stage is a discrete sine wave f(x) recorded in a periodic data window. Since the sampling frequency in this stage is 1 MHz, the duration of one period is 25 μs. Therefore, if 25 sample points are taken, the step size is 1 μs. If the number of samples is changed, the sample interval will change accordingly. The more samples taken, the smaller the sample interval will be (the number of samples × sample interval = 25 μs must be satisfied). The parasitic voltage data during normal operation is represented as a p-dimensional vector (in this embodiment, p is 25, and the interval between samples is 1 μs):

[0262] x i =[x i,1 x i,2 x i,3 x i,4 … x i,p ]

[0263] Where x i represents the registered voltage data of the i-th transmission line when it is working normally, i = 1, 2, 3, ... n; x i,p represents the pth sample of the registered voltage data when the i-th transmission line is operating normally;

[0264] A total of n (n is 2400 in this embodiment) parasitic voltage data of transmission lines in normal operation are used to form the matrix X:

[0265]

[0266] Wherein, x(n,p) represents the p-th sample of the n-th registered voltage data when the transmission line operates normally.

[0267] Calculate the mean vector of the normalized matrix J of the X matrix The calculation method is:

[0268]

[0269] Where j(i,p) represents the value of the i-th row and p-th column of the normalized matrix J of the X matrix; i = 1, 2, 3, ... n;

[0270] Calculate the variance-covariance matrix S as follows:

[0271]

[0272] Where, ji Represents the row vector of the i-th row (1×p) of the normalized matrix J matrix;

[0273] Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S, where the eigenvectors are represented by μ (25 eigenvectors are required in this embodiment):

[0274] μ1=[μ 1,1 ,μ 1,2 ,μ 1,3 …,μ 1,p ] T

[0275] μ2=[μ 2,1 ,μ 2,2 ,μ 2,3 …,μ 2,p ] T

[0276] …

[0277] μ n =[μ n,1 ,μ n,2 ,μ n,3 …,μ n,p ] T

[0278] Where μ n represents the nth eigenvector of the variance-covariance matrix S; μ n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S;

[0279] The eigenvalue is represented by λ (25 eigenvalues ​​are required in this embodiment):

[0280] λ=[λ1,λ2,λ3,...,λ p ]

[0281] Where λ p represents the pth eigenvalue of the variance-covariance matrix S;

[0282] Calculate the principal component data (n×p) of the register voltage data using the following method:

[0283]

[0284] Where z n Represents the principal component data of the calculated n-th register voltage data, which is a 1×p row vector; μ n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S; j represents each row vector of the normalized matrix J; μ TRepresents the transpose of the matrix consisting of the n eigenvectors of the variance-covariance matrix S.

[0285] In the present invention, the elliptical equation corresponding to the elliptical coordinate system when the transmission line operates normally is:

[0286]

[0287] Where EE is the calculated value of the ellipse equation, PC is 1r and PC 2r Represents the first two principal component data of any phase of the elliptical pattern during normal operation (these two principal component data determine a coordinate point, which is equivalent to the values ​​of x and y in the xy axis coordinate system), that is, (PC 1r , PC 2r ) is the coordinate point corresponding to any phase in the principal component coordinate system; PC 1max Represents the major semi-axis of the elliptical pattern; PC 2max Represents the semi-minor axis of the ellipse pattern.

[0288] Furthermore, in the present invention, principal component analysis is performed on the real-time voltage data of the transmission line, and the specific method for obtaining the principal component data of the real-time voltage data is:

[0289] The n real-time voltage data of the transmission line are analyzed in different data windows of p samples, with an interval of 1 μs between samples. The real-time voltage data of the transmission line are represented as a p-dimensional vector:

[0290] x′ i =[x′ i,1 x′ i,2 x′ i,3 x′ i,4 … x′ i,p ]

[0291] Where x' i represents the i-th real-time voltage data, i=1, 2, 3, ... n; x' i,p represents the pth sample of the i-th real-time voltage data;

[0292] The real-time voltage data of n transmission lines are used to form the matrix X':

[0293]

[0294] Where x'(n,p) represents the pth sample of the nth real-time voltage data of the transmission line;

[0295] Calculate the mean vector of the normalized matrix J' of the X' matrix , the calculation method is:

[0296]

[0297] Where j'(i,p) represents the value of the i-th row and p-th column of the normalized matrix J' of the X' matrix; i = 1, 2, 3, ... n;

[0298] Calculate the variance-covariance matrix S' using the following method:

[0299]

[0300] Where, j' i Represents the row vector of the i-th row (1×p) of the normalized matrix J'.

[0301] Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S', and the eigenvector is represented by μ':

[0302] μ′1=[μ′ 1,1 ,μ′ 1,2 ,μ′ 1,3 …,μ′ 1,p ] T

[0303] μ′2=[μ′ 2,1 ,μ′ 2,2 ,μ′ 2,3 …,μ′ 2,p ] T

[0304] …

[0305] μ′ n =[μ′ n,1 ,μ′ n,2 ,μ′ n,3 …,μ′ n,p ] T

[0306] Where μ' n represents the nth eigenvector of the variance-covariance matrix S'; μ' n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S';

[0307] The eigenvalue is denoted by λ':

[0308] λ′=[λ′1,λ′2,λ′3,...,λ′ p ]

[0309] Where λ' p represents the pth eigenvalue of the variance-covariance matrix S';

[0310] Calculate the principal component data (n×p) of the real-time voltage data using the following method:

[0311]

[0312] Where z' n Represents the calculated principal component data of the nth real-time voltage data, which is a 1×p row vector; represents the transposed vector of the nth eigenvector of the variance-covariance matrix S'; j' represents each row vector of the normalized matrix J'; μ' T Represents the transpose of the matrix consisting of the nth eigenvectors of the variance-covariance matrix S'.

[0313] In the present invention, the principal component data of the real-time voltage data is projected onto the elliptical coordinate system when the transmission line is operating normally, wherein the principal component values ​​of the real-time voltage data located outside and within the boundary of the elliptical coordinate system when the transmission line is operating normally (i.e., the real-time voltage data not on the boundary of the elliptical coordinate system when the transmission line is operating normally; the principal component data of the real-time voltage data can be substituted into the elliptical equation corresponding to the elliptical coordinate system when the transmission line is operating normally to calculate the EE value corresponding to the real-time voltage data, and the calculated EE is used to determine whether the real-time voltage data is on the boundary of the elliptical coordinate system when the transmission line is operating normally; when EE is less than 1, it means that the real-time voltage data is inside the boundary of the elliptical coordinate system when the transmission line is operating normally; when EE is greater than 1, it means that the real-time voltage data is outside the boundary of the elliptical coordinate system when the transmission line is operating normally, that is, exceeds the boundary of the elliptical coordinate system; when EE=1, it means that the real-time voltage data is on the boundary of the elliptical coordinate system when the transmission line is operating normally, which represents a normal operating state) show a certain regularity, indicating the trajectory of the interference type. Based on this feature, the Euclidean tolerance EN between these principal component values ​​and the origin (0, 0) of the elliptical coordinate system when the transmission line is working normally can be calculated to determine the type of interference phenomenon.

[0314] Furthermore, based on the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally, the specific method for determining the lightning transient signal on the transmission line using the elliptical algorithm is as follows:

[0315] The Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated using the following method:

[0316]

[0317] Where Δdk represents the Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the original elliptical coordinate system when the transmission line is operating normally; f irepresents the elliptical coordinates corresponding to the i-th real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally; f o represents the coordinates (0, 0) of the origin of the elliptical coordinate system when the transmission line is operating normally; h represents the number of principal component data of the real-time voltage data located outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally;

[0318] The Euclidean tolerance EN between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated as follows:

[0319]

[0320] The components for distinguishing lightning transient signals on transmission lines are as follows:

[0321]

[0322] In the formula, F represents a logical value, which is used as a discriminant element. The identification of the interference type is achieved by calculating the normalized values ​​of n new continuous vectors. Since the Euclidean normal value of the switching operation is less than the lightning strike, if the Euclidean normal value is less than or equal to the threshold, that is, F = 0, then the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a switching operation (transmission line switching operation is a power system technical measure used to adjust the phase sequence of one or more transmission lines in the power grid; switching operation can also cause traveling wave anomalies, but it is not a lightning strike point fault). When F = 1, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a lightning transient signal on the transmission line; ε is a threshold (the threshold in the present invention is determined based on the specific situation in actual application and can be selected by multiple simulations of lightning strike faults and normal operation conditions).

[0323] In the technical solution of the present invention, the voltage traveling wave of the lightning transient signal on the transmission line is detected, and the specific method for determining the location of the lightning strike point based on the voltage traveling wave of the lightning transient signal on the transmission line using the traveling wave transmission theory is as follows:

[0324] Detecting a voltage traveling wave of a lightning transient signal on a transmission line, collecting voltage data points of the voltage traveling wave, and determining, according to a counting scheme, a number s1 of voltage data points of the voltage traveling wave detected by a front-end protection relay of the transmission line and a number s2 of voltage data points of the voltage traveling wave detected by a rear-end protection relay of the transmission line;

[0325] When s1 < s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is:

[0326] Δt=Sa ×(s1 - s2)

[0327]

[0328] Wherein, t1 is the time for the voltage traveling wave to propagate from the lightning strike point to the front-end protection relay of the transmission line, t2 is the time for the voltage traveling wave to propagate from the lightning strike point to the rear-end protection relay of the transmission line, Δt is the time difference between t1 and t2, and t total represents the sum of t1 and t2, and S a represents the sampling rate of the protection relay (the sampling rate of the front-end protection relay is the same as that of the rear-end protection relay);

[0329] When s1 > s2, the time for the voltage traveling wave to propagate from the lightning strike point to the two-end protection relays is calculated, and the expression is:

[0330] Δt = S a ×(s1 - s2)

[0331]

[0332] The method for calculating the distance of the lightning strike point based on the time for the voltage traveling wave to propagate from the lightning strike point to the two-end protection relays is:

[0333] d1 = ct1

[0334] d2 = ct2

[0335] Wherein, d1 represents the distance from the lightning strike point to the front-end protection relay; d2 represents the distance from the lightning strike point to the rear-end protection relay; c represents the propagation speed of the voltage traveling wave.

[0336] In the present invention, after calculating d1 and d2, the lightning strike point distance results d1 and d2 can be output.

[0337] In the present invention, the principle of calculating the lightning strike point distance is as follows:

[0338] When a lightning strike fault occurs at point F on the transmission line, a fault voltage traveling wave that propagates towards both ends of the line will be generated from the lightning strike fault point F. d1 and d2 are respectively the distances from the lightning strike fault point F to the measurement end R (front-end protection relay) and the measurement end I (rear-end protection relay), L is the total length of the transmission line, t1 is the time for the fault voltage traveling wave to propagate from the lightning strike fault point to the measurement end R, t2 is the time for the fault voltage traveling wave to propagate from the lightning strike fault point to the measurement end I, and t total represents the sum of t1 and t2, that is, the time for the fault voltage traveling wave to propagate from the front-end protection relay to the rear-end protection relay; when s1 < s2 (i.e., d1 < d2), as Figure 2As shown, the measuring terminal R receives the forward fault voltage traveling wave propagating from the lightning fault point, and the measuring terminal I receives the backward fault voltage traveling wave propagating from the lightning fault point. The corresponding formula can be used to calculate Δt, t1, and t2. When s1>s2 (i.e., d1>d2), as shown Figure 3 As shown, the measuring terminal R receives the fault voltage traveling wave propagated from the lightning fault point, and the measuring terminal I receives the fault voltage traveling wave propagated from the lightning fault point. The corresponding formula can be used to calculate Δt, t1, and t2; and then the distance to the lightning strike point can be further calculated.

[0339] Example 3

[0340] A computer-readable storage medium stores a computer program, wherein the computer program implements the steps of embodiment 2 when executed by a processor.

[0341] It should be understood that parts not elaborated in detail in this specification belong to the prior art.

[0342] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A transmission line lightning strike point location system, characterized in that: include: The elliptical coordinate system construction module is used to perform principal component analysis on the parasitic voltage data when the transmission line is operating normally, obtain principal component data of the parasitic voltage data, project the principal component data of the parasitic voltage data onto the principal component coordinate system, and construct the elliptical coordinate system when the transmission line is operating normally; The lightning signal screening module is used to perform principal component analysis on the real-time voltage data of the transmission line, obtain the principal component data of the real-time voltage data, project the principal component data of the real-time voltage data into an elliptical coordinate system when the transmission line is operating normally, screen out the real-time voltage data located outside and inside the boundary of the elliptical coordinate system, and determine the lightning transient signal on the transmission line using an elliptical algorithm based on the real-time voltage data located outside and inside the boundary of the elliptical coordinate system; The lightning strike point distance location module is used to detect the voltage traveling wave of the lightning transient signal on the transmission line. Based on the voltage traveling wave of the lightning transient signal on the transmission line, the location of the lightning strike point is determined by the traveling wave transmission theory. The elliptical equation corresponding to the elliptical coordinate system when the transmission line is operating normally is: Where EE is the calculated value of the ellipse equation, PC is 1r and PC 2r Represents the first two principal component data of any phase of the elliptical pattern during normal operation; PC 1max represents the major semi-axis of the elliptical pattern; PC 2max represents the minor semi-axis of the elliptical pattern; The specific method for detecting the voltage traveling wave of the lightning transient signal on the transmission line and determining the location of the lightning strike point based on the voltage traveling wave of the lightning transient signal on the transmission line using the traveling wave transmission theory is as follows: Detecting a voltage traveling wave of a lightning transient signal on a transmission line, collecting voltage data points of the voltage traveling wave, and determining, according to a counting scheme, a number s1 of voltage data points of the voltage traveling wave detected by a front-end protection relay of the transmission line and a number s2 of voltage data points of the voltage traveling wave detected by a rear-end protection relay of the transmission line; When s1 < s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is: Δt=S a ×(s1-s2) Where t1 is the time it takes for the voltage traveling wave to propagate from the lightning strike point to the front-end protection relay of the transmission line, t2 is the time it takes for the voltage traveling wave to propagate from the lightning strike point to the rear-end protection relay of the transmission line, Δt is the time difference between t1 and t2, and t total Indicates t1 and The sum of t2, S a Indicates the sampling rate of the protection relay; When s1>s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is: Δt=S a ×(s1-s2) The method for calculating the distance from the lightning strike point based on the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends is: d1=ct1 d2=ct2 Where d1 represents the distance from the lightning strike point to the front-end protection relay; d2 represents the distance from the lightning strike point to the rear-end protection relay; and c represents the speed of voltage traveling wave propagation.

2. The transmission line lightning strike point locating system according to claim 1, characterized in that: The specific method of performing principal component analysis on the parasitic voltage data when the transmission line is operating normally and obtaining the principal component data of the parasitic voltage data includes: The n parasitic voltage data of the transmission line during normal operation are analyzed in different data windows of p samples, and the parasitic voltage data during normal operation are expressed as a p-dimensional vector: x i =[x i,1 x i,2 x i,3 x i,4 ···x i,p ] Where x i represents the registered voltage data of the i-th transmission line when it is working normally, i = 1, 2, 3, ... n; x i,p represents the pth sample of the registered voltage data when the i-th transmission line is operating normally; A total of n transmission lines' parasitic voltage data when operating normally are used to form the matrix X: Where x(n,p) represents the pth sample of the nth registered voltage data when the transmission line is operating normally; Calculate the mean vector of the normalized matrix J of the X matrix The calculation method is: Where j(i,p) represents the value of the i-th row and p-th column of the normalized matrix J of the X matrix, i = 1, 2, 3, ... n; Calculate the variance-covariance matrix S as follows: Where, j i Represents the row vector of the i-th row of the normalized matrix J matrix; Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S, and the eigenvector is represented by μ: μ1=[μ 1,1 ,m 1,2 ,m 1,3 ···,m 1,p ] T μ2=[μ 2,1 ,m 2,2 ,m 2,3 ···,m 2,p ] T …… m n =[μ n,1 ,m n,2 ,m n,3 ···,m n,p ] T Where μ n represents the nth eigenvector of the variance-covariance matrix S; μ n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S; The eigenvalue is denoted by λ: λ=[λ1,λ2,λ3,...,λ p ] Where λ p represents the pth eigenvalue of the variance-covariance matrix S; Calculate the principal component data of the registered voltage data using the following method: Where z n Represents the principal component data of the calculated nth register voltage data, which is a 1×p row vector; μ n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S; j represents each row vector of the normalized matrix J; μ T Represents the transpose of the matrix consisting of the n eigenvectors of the variance-covariance matrix S.

3. The transmission line lightning strike point locating system according to claim 1, characterized in that: The specific method of performing principal component analysis on the real-time voltage data of the transmission line and obtaining the principal component data of the real-time voltage data is as follows: The n real-time voltage data of the transmission line are analyzed in different data windows of p samples, with an interval of 1 μs between samples. The real-time voltage data of the transmission line are represented as a p-dimensional vector: x′ i =[x′ i,1 x′ i,2 x′ i,3 x′ i,4 ···x′ i,p ] Where x' i represents the i-th real-time voltage data, i=1, 2, 3, ... n; x' i,p represents the pth sample of the i-th real-time voltage data; The real-time voltage data of n transmission lines are used to form the matrix X': Where x'(n,p) represents the pth sample of the nth real-time voltage data of the transmission line; Calculate the mean vector of the normalized matrix J' of the X' matrix The calculation method is: Where j'(i,p) represents the value of the i-th row and p-th column of the normalized matrix J' of the X' matrix; i = 1, 2, 3, ... n; Calculate the variance-covariance matrix S' using the following method: Where, j' i Represents the row vector of the i-th row of the normalized matrix J'; Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S', and the eigenvector is represented by μ': μ′1=[μ′ 1,1 ,m′ 1,2 ,m′ 1,3 ···,μ′ 1,p ] T μ′2=[μ′ 2,1 ,m′ 2,2 ,m′ 2,3 ···,μ′ 2,p ] T …… m′ n =[μ′ n,1 ,m′ n,2 ,m′ n,3 ···,μ′ n,p ] T Where μ' n represents the nth eigenvector of the variance-covariance matrix S'; μ' n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S'; The eigenvalue is denoted by λ': λ′=[λ′1,λ′2,λ′3,...,λ′ p ] Where λ' p represents the pth eigenvalue of the variance-covariance matrix S'; Calculate the principal component data of real-time voltage data using the following method: Where z' n represents the principal component data of the calculated n-th real-time voltage data, which is a 1×p row vector; μ' n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S'; j' represents each row vector of the normalized matrix J'; μ' T Represents the transpose of the matrix consisting of the nth eigenvectors of the variance-covariance matrix S'.

4. The transmission line lightning strike point locating system according to claim 1, characterized in that: Based on the real-time voltage data outside and inside the boundary of the elliptical coordinate system, the specific method for determining the lightning transient signal on the transmission line using the elliptical algorithm is as follows: The Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated using the following method: Where Δdk represents the Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the origin of the elliptical coordinate system when the transmission line is operating normally; f i represents the elliptical coordinates corresponding to the i-th real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally; f o represents the coordinates of the origin of the elliptical coordinate system when the transmission line is operating normally; h represents the number of principal component data of the real-time voltage data located outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally; The Euclidean tolerance EN between the real-time voltage data outside and inside the boundary of the elliptical coordinate system and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated as follows: The components for distinguishing lightning transient signals on transmission lines are as follows: Wherein, F represents a logical value. When F=0, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a switching operation. When F=1, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a lightning transient signal on the transmission line. ε is the threshold.

5. A method for locating a lightning strike point on a transmission line, characterized in that: include: Performing principal component analysis on the parasitic voltage data when the transmission line is operating normally to obtain principal component data of the parasitic voltage data, projecting the principal component data of the parasitic voltage data onto a principal component coordinate system, and constructing an elliptical coordinate system when the transmission line is operating normally; Performing principal component analysis on the real-time voltage data of the transmission line to obtain principal component data of the real-time voltage data, projecting the principal component data of the real-time voltage data into an elliptical coordinate system when the transmission line is operating normally, screening out real-time voltage data located outside and inside the boundary of the elliptical coordinate system, and determining the lightning transient signal on the transmission line using an elliptical algorithm based on the real-time voltage data located outside and inside the boundary of the elliptical coordinate system; Detect the voltage traveling wave of the lightning transient signal on the transmission line, and determine the location of the lightning strike point based on the voltage traveling wave of the lightning transient signal on the transmission line using the traveling wave transmission theory; The elliptical equation corresponding to the elliptical coordinate system when the transmission line is operating normally is: Where EE is the calculated value of the ellipse equation, PC is 1r and PC 2r Represents the first two principal component data of any phase of the elliptical pattern during normal operation; PC 1max represents the major semi-axis of the elliptical pattern; PC 2max represents the minor semi-axis of the elliptical pattern; The specific method for detecting the voltage traveling wave of the lightning transient signal on the transmission line and determining the location of the lightning strike point based on the voltage traveling wave of the lightning transient signal on the transmission line using the traveling wave transmission theory is as follows: Detecting a voltage traveling wave of a lightning transient signal on a transmission line, collecting voltage data points of the voltage traveling wave, and determining, according to a counting scheme, a number s1 of voltage data points of the voltage traveling wave detected by a front-end protection relay of the transmission line and a number s2 of voltage data points of the voltage traveling wave detected by a rear-end protection relay of the transmission line; When s1 < s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is: Δt=S a ×(s1-s2) Where t1 is the time it takes for the voltage traveling wave to propagate from the lightning strike point to the front-end protection relay of the transmission line, t2 is the time it takes for the voltage traveling wave to propagate from the lightning strike point to the rear-end protection relay of the transmission line, Δt is the time difference between t1 and t2, and t total represents the sum of t1 and t2, S a Indicates the sampling rate of the protection relay; When s1>s2, calculate the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends. The expression is: Δt=S a ×(s1-s2) The method for calculating the distance from the lightning strike point based on the time it takes for the voltage traveling wave to propagate from the lightning strike point to the protective relays at both ends is: d1=ct1 d2=ct2 Where d1 represents the distance from the lightning strike point to the front-end protection relay; d2 represents the distance from the lightning strike point to the rear-end protection relay; and c represents the speed of voltage traveling wave propagation.

6. The method for locating the lightning strike point of a transmission line according to claim 5, characterized in that: The specific method of performing principal component analysis on the parasitic voltage data when the transmission line is operating normally and obtaining the principal component data of the parasitic voltage data includes: The n parasitic voltage data of the transmission line during normal operation are analyzed in different data windows of p samples, and the parasitic voltage data during normal operation are expressed as a p-dimensional vector: x i =[x i,1 x i,2 x i,3 x i,4 ···x i,p ] Where x i represents the registered voltage data of the i-th transmission line when it is working normally, i = 1, 2, 3, ... n; x i,p represents the pth sample of the registered voltage data when the i-th transmission line is operating normally; A total of n transmission lines' parasitic voltage data when operating normally are used to form the matrix X: Where x(n,p) represents the pth sample of the nth registered voltage data when the transmission line is operating normally; Calculate the mean vector of the normalized matrix J of the X matrix The calculation method is: Where j(i,p) represents the value of the i-th row and p-th column of the normalized matrix J of the X matrix; i = 1, 2, 3, ... n; Calculate the variance-covariance matrix S as follows: Where, j i Represents the row vector of the i-th row of the normalized matrix J matrix; Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S, and the eigenvector is represented by μ: μ1=[μ 1,1 ,m 1,2 ,m 1,3 ···,m 1,p ] T μ2=[μ 2,1 ,m 2,2 ,m 2,3 ···,m 2,p ] T …… m n =[μ n,1 ,m n,2 ,m n,3 ···,m n,p ] T Where μ n represents the nth eigenvector of the variance-covariance matrix S; μ n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S; The eigenvalue is denoted by λ: λ=[λ1,λ2,λ3,...,λ p ] Where λ p represents the pth eigenvalue of the variance-covariance matrix S; Calculate the principal component data of the registered voltage data using the following method: Where z n Represents the principal component data of the calculated nth register voltage data, which is a 1×p row vector; μ n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S; j represents each row vector of the normalized matrix J; μ T Represents the transpose of the matrix consisting of the n eigenvectors of the variance-covariance matrix S.

7. The method for locating the lightning strike point of a transmission line according to claim 5, characterized in that: The specific method of performing principal component analysis on the real-time voltage data of the transmission line and obtaining the principal component data of the real-time voltage data is as follows: The n real-time voltage data of the transmission line are analyzed in different data windows of p samples, with an interval of 1 μs between samples. The real-time voltage data of the transmission line are represented as a p-dimensional vector: x′ i =[x′ i,1 x′ i,2 x′ i,3 x′ i,4 ···x′ i,p ] Where x' i represents the i-th real-time voltage data, i=1, 2, 3, ... n; x' i,p represents the pth sample of the i-th real-time voltage data; The real-time voltage data of n transmission lines are used to form the matrix X': Where x'(n,p) represents the pth sample of the nth real-time voltage data of the transmission line; Calculate the mean vector of the normalized matrix J' of the X' matrix The calculation method is: Where j'(i,p) represents the value of the i-th row and p-th column of the normalized matrix J' of the X' matrix; i = 1, 2, 3, ... n; Calculate the variance-covariance matrix S' using the following method: Where, j' i Represents the row vector of the i-th row of the normalized matrix J'; Calculate the eigenvalues ​​and eigenvectors of the variance-covariance matrix S', and the eigenvector is represented by μ': μ′1=[μ′ 1,1 ,m′ 1,2 ,m′ 1,3 ···,μ′ 1,p ] T μ′2=[μ′ 2,1 ,m′ 2,2 ,m′ 2,3 ···,μ′ 2,p ] T …… m′ n =[μ′ n,1 ,m′ n,2 ,m′ n,3 ···,μ′ n,p ] T Where μ' n represents the nth eigenvector of the variance-covariance matrix S'; μ' n，p represents the pth value of the nth eigenvector of the variance-covariance matrix S'; The eigenvalue is denoted by λ': λ′=[λ′1,λ′2,λ′3,...,λ′ p ] Where λ' p represents the pth eigenvalue of the variance-covariance matrix S'; Calculate the principal component data of real-time voltage data using the following method: Where z' n represents the principal component data of the calculated n-th real-time voltage data, which is a 1×p row vector; μ' n T represents the transposed vector of the nth eigenvector of the variance-covariance matrix S'; j' represents each row vector of the normalized matrix J'; μ' T Represents the transpose of the matrix consisting of the nth eigenvectors of the variance-covariance matrix S'.

8. The method for locating the lightning strike point of a transmission line according to claim 5, characterized in that: Based on the real-time voltage data outside and inside the boundary of the elliptical coordinate system, the specific method for determining the lightning transient signal on the transmission line using the elliptical algorithm is as follows: The Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated using the following method: Where Δdk represents the Euclidean distance between the real-time voltage data outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally and the original elliptical coordinate system when the transmission line is operating normally; f i represents the elliptical coordinates corresponding to the i-th real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally; f o represents the coordinates of the origin of the elliptical coordinate system when the transmission line is operating normally; h represents the number of principal component data of the real-time voltage data located outside and inside the boundary of the elliptical coordinate system when the transmission line is operating normally; The Euclidean tolerance EN between the real-time voltage data outside and inside the boundary of the elliptical coordinate system and the origin of the elliptical coordinate system when the transmission line is operating normally is calculated as follows: The components for distinguishing lightning transient signals on transmission lines are as follows: Wherein, F represents a logical value. When F=0, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a switching operation. When F=1, the real-time voltage data located outside or inside the boundary of the elliptical coordinate system when the transmission line is operating normally is identified as a lightning transient signal on the transmission line. ε is the threshold.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 5 to 8 are implemented.

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